Higher-Level Systematics of the Recent Sauropsida

When asked for an example of “paraphyly”, the easiest case to give is that of reptiles. The clade “Reptilia” classically comprises the turtles, lizards, snakes, crocodiles, and dinosaurs, and leaves birds out – even though birds are dinosaurs. So unless you explicitly state that you count birds as reptiles, you’re talking of a paraphyletic taxon. The correct name for the clade, Reptilia including birds, is Sauropsida (although they are nowadays used synonymously).